The present invention relates to hubcaps and, more particularly, to a novel type of hub and a hubcap assembly for trucks and the like. The hub unit includes one set of screw threads, a plurality of notches in the flat surfaces on the radially extending sealing surfaces on the hub, and a hubcap with matching threads, a closed end and a discontinuous radial flange with at least one resilient latching tab in the discontinuity. One or more latching tab contain a formation adapted to fit in one of the notches. In one embodiment, a contoured circumferential cutout in the threaded portion of the hub accommodates a resilient O-ring or similar gasket.
The novel hubcap assembly preferably incorporates two latching tabs and a plurality, preferably 8 to 16, of notches to accommodate formations on the latching tabs. The tabs are biased by their own innate resiliency to urge the formations on the tabs into the contoured notches, and can be displaced therefrom by lifting against this resilient force. The latching formations on the tabs preferably include a rear, perpendicular or axial surface, a flat, offset surface parallel to the radial flange surfaces, and a transition or inclined surface to facilitate entry into the notches. The formation is located outwardly on the tab, and the tab may have a further, finger-engaging portion on the tab to facilitate lifting the tab out of engagement with the notch when it is desired to release the engagement between the tab formation and the notches.
In the prior art, most hubcaps, particularly truck hubcaps, have been positioned and fastened by a gasket and a number of bolts, studs or cap screws. This has caused the outer portion of the hub to be thicker than necessary, to receive the shank portion of bolts or studs. Otherwise, a flange might extend into the center of the hub, again adding difficulty in manufacturing or having other drawbacks. A few prior art hub caps have been screwed onto the hubs, but these hubcaps have lacked the latching feature and other advantages of the present invention. Consequently, these hubcaps were liable to unscrew unintentionally.
Naturally, with at least six, and occasionally as many as twelve bolts or studs for every hub, the parts count for each hub is undesirably high. In use, each stud or bolt should be torqued evenly; failure to do so may cause leakage or even failure.
With the hubcap of the present invention on the other hand, the hubcap may be screwed into any desired degree of tightness, either by applying a force by hand tightening, or with a wrench or the like, or both, of course.
Accordingly, it is an object of the invention to provide an improved, readily removable hubcap for use on a specially designed hub.
Another object is to provide a hubcap having a threaded portion on its open end and adapted to mate with a tapped or threaded hub having locking means thereon.
A further object is to provide a hubcap which can easily be attached to a hub, and tightened to any desired degree, but which cannot be accidentally loosened or removed from its installed position.
A still further object is to provide a hubcap having one or more latching tabs, at least one of which automatically engages one or more specially designed notches and which cannot be removed without intentionally biasing the latching tabs away from the notches.
A further object is to provide one or more latching tabs which flex sufficiently to enable them to be readily removed from a notch or detent.
Another object is to provide one or more latching tabs which in some embodiments are flexible compared to the radial flange with which they are radially aligned.
A still further object is to provide a hubcap with latching tabs and a hexagonal or octagonal formation on its closed end to enable it to be grasped by a wrench when installing it to its desired torque.
A further object of the invention is to provide a hubcap made from a tough plastic material.